1. Technical Field
This invention is in the field of liquid handling devices, and more specifically is in the field of pipet guns for drawing liquid into and expelling liquid from a pipet.
2. Related Inventions
This invention is related to the inventions shown in U.S. Pat. Nos. 3,963,061; 3,834,240; and U.S. Pat. No. Des. 242,729, all of which are owned by Drummond Scientific Company, Broomall, Pa. and all of which are incorporated herein by reference.
3. Background of the Prior Art
The present pipet gun is an improvement over those shown in my previously granted U.S. Pat. No. 3,963,061 of June 15, 1976, U.S. Pat. No. 3,834,240 of Sept. 10, 1974, and U.S. Pat. No. Des. 242,729 granted Dec. 14, 1976.
As pointed out in previous patents, the practice of mouth pipetting liquid samples can be harmful, and the practice has been prohibited in many laboratories. Mechanical devices have been developed in an attempt to replace mouth pipetting, but many of these devices are cumbersome to operate and can cause operator fatigue.
My previous pipet guns have been commercially successful, and the present invention is an improvement. It is particularly directed to a pipet gun having an improved valve body which is less expensive to manufacture.